CVE-2026-45267 Nextcloud: Missing permission check for from submissions
Attackers can read other users' form submissions due to missing permission checks in the Nextcloud Forms application.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-45267?
CVE-2026-45267 is a medium-severity missing authorization vulnerability in nextcloud security-advisories, published on 1 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Nextcloud is an open source content collaboration platform. Prior to version 5.2.6, a missing permissions check allowed users to request reading form submissions of other users. This issue has been patched in version 5.2.6.
Which versions are affected by CVE-2026-45267?
How do I fix CVE-2026-45267?
No fix has been published for CVE-2026-45267 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-45267 being exploited?
There is no known exploitation of CVE-2026-45267 in the wild and no public exploit code.
Sources
Also known as GHSA-r4gh-f8x6-m55f.